As is well known, any complex logic function results from a combination of simple basic functions involving, in particular, AND and OR logic operations. The process made in the field of large scale integration (LSI) techniques has enabled manufacturers to develop and market new types of circuits called programmable logic arrays (PLAs) which are essentially comprised of matrices of elements performing AND and OR logic functions. In its simplest form, such a circuit comprises a matrix of AND circuits designated "AND matrix" and a matrix of OR circuits designated "OR matrix". The data to be processed are generally inputted to the AND matrix, which performs logic combinations of the AND type involving the input data and their complemented values. The terms provided by this matrix are then fed to the OR matrix where they are subjected to OR type logic operations. For some applications, the desired result is obtained at the output of the OR matrix, but other applications make it necessary to perform recurrent operations. In other words, data obtained at the output of the OR matrix is fed back to the input of the AND matrix. The desired result is then obtained upon completion of a sequential process, certain steps of which make use of the results obtained during the immediately preceding step. For the purposes of these functions, an output register is provided at the output of the OR matrix and the output of this register is connected to the input of the AND matrix. Although these logic arrays are termed "programmable", they do not have the ability to alter logic functions dynamically at the option of the programmer. In order to change functions, at least one of the matrices must be changed.